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Column chromatography is an extremely time-consuming stage in any lab and can quickly become the bottleneck for any process lab. Many manufacturers like Biotage, Buchi, Interchim and Teledyne Isco have developed automated flash chromatography systems (typically referred to as LPLC, low pressure liquid chromatography, a... | 0 | Chromatography + Titration + pH indicators |
The electronic density functional is explicitly used in the calculation of the electronic ground state. Packages such as VASP have an option to calculate the electronic density of states per eV to facilitate the prediction of conduction bands and band gaps. | 1 | Crystallography |
In X-ray crystallography, crystallographic disorder describes the cocrystallization of more than one rotamer, conformer, or isomer where the center of mass of each form is identical or unresolvable. As a consequence of disorder, the crystallographic solution is the sum of the various forms. In many cases, the compone... | 1 | Crystallography |
The Uhlenhuth test, or the antigen–antibody precipitin test for species, was invented by Paul Uhlenhuth in 1901 and could distinguish human blood from animal blood, based on the discovery that the blood of different species had one or more characteristic proteins. The test represented a major breakthrough and came to h... | 0 | Chromatography + Titration + pH indicators |
A quasiperiodic crystal, or quasicrystal, is a structure that is ordered but not periodic. A quasicrystalline pattern can continuously fill all available space, but it lacks translational symmetry. While crystals, according to the classical crystallographic restriction theorem, can possess only two-, three-, four-, and... | 1 | Crystallography |
In physics, a phason is a form of collective excitation found in aperiodic crystal structures. Phasons are a type of quasiparticle: an emergent phenomenon of many-particle systems. Similar to phonons, phasons are quasiparticles associated with atomic motion. However, whereas phonons are related to the translation of at... | 1 | Crystallography |
Light alone does not rapidly degrade methyl violet, but the process is accelerated upon the addition of large band-gap semiconductors, TiO or ZnO. | 0 | Chromatography + Titration + pH indicators |
Thin-layer chromatography (TLC) is a chromatography technique that separates components in non-volatile mixtures.
It is performed on a TLC plate made up of a non-reactive solid coated with a thin layer of adsorbent material. This is called the stationary phase. The sample is deposited on the plate, which is eluted with... | 0 | Chromatography + Titration + pH indicators |
Synthetic perovskites are possible materials for high-efficiency photovoltaics – they showed a conversion efficiency of up to 26.3% and can be manufactured using the same thin-film manufacturing techniques as that used for thin film silicon solar cells. Methylammonium tin halides and methylammonium lead halides are of ... | 1 | Crystallography |
Protein crystallization is governed by the same physics that governs the formation of inorganic crystals. For crystallization to occur spontaneously, the crystal state must be favored thermodynamically. This is described by Gibb's free energy (∆G), defined as ∆G = ∆H- T∆S, which captures how the energetics of a process... | 1 | Crystallography |
Despite the reduced efficiency verses reversed phase HPLC, hundreds of applications have been reported using MLC. One of the most advantageous is the ability to directly inject physiological fluids. Micelles have an ability to solubilize proteins which enables MLC to be useful in analyzing untreated biological fluids... | 0 | Chromatography + Titration + pH indicators |
In crystallography, a lattice plane of a given Bravais lattice is any plane containing at least three noncollinear Bravais lattice points. Equivalently, a lattice plane is a plane whose intersections with the lattice (or any crystalline structure of that lattice) are periodic (i.e. are described by 2d Bravais lattices)... | 1 | Crystallography |
A crystal structure is defined as the spatial distribution of the atoms within a crystal, usually modeled by the idea of an infinite crystal pattern. An infinite crystal pattern refers to the infinite 3D periodic array which corresponds to a crystal, in which the lengths of the periodicities of the array may not be mad... | 1 | Crystallography |
The spacing d between adjacent (hkℓ) lattice planes is given by:
*Cubic:
*Tetragonal:
*Hexagonal:
*Rhombohedral (primitive setting):
*Orthorhombic:
*Monoclinic:
*Triclinic: | 1 | Crystallography |
Precession electron diffraction is typically conducted using accelerating voltages between 100-400 kV. Patterns can be formed under parallel or convergent beam conditions. Most modern TEMs can achieve a tilt angle, φ, ranging from 0-3°. Precession frequencies can be varied from Hz to kHz, but in standard cases 60 Hz ha... | 1 | Crystallography |
In powder samples there is a tendency for plate- or rod-like crystallites to align themselves along the axis of a cylindrical sample holder. In solid polycrystalline samples the production of the material may result in greater volume fraction of certain crystal orientations (commonly referred to as texture). In such ca... | 1 | Crystallography |
Composition of isometries mixes kinds in assorted ways. We can think of the identity as either two mirrors or none; either way, it has no effect in composition. And two reflections give either a translation or a rotation, or the identity (which is both, in a trivial way). Reflection composed with either of these could ... | 1 | Crystallography |
Methyl orange has mutagenic properties. When methyl orange is put under oxidative stress, one of the double-bonded nitrogen atoms that connects the aromatic rings gets radicalized and can further break down into reactive oxygen species or anilines, which are carcinogenic and can mutate DNA. Various bacteria and enzymes... | 0 | Chromatography + Titration + pH indicators |
When the dimension of the lattice rises to four or more, rotations need no longer be planar; the 2D proof is inadequate. However, restrictions still apply, though more symmetries are permissible. For example, the hypercubic lattice has an eightfold rotational symmetry, corresponding to an eightfold rotational symmetry ... | 1 | Crystallography |
Brown MX-5BR or Reactive Brown 10 has a formula of CHClCrNNaOS and a molecular weight of 1163.6 g/mol, containing two dichlorotriazine rings. Brown MX-5BR, for example, can be used to purify lysozyme, phosphinothricin acetyltransferase. It also shown that it can elute tryptophanyl-tRNA synthetase using Trp as eluant, ... | 0 | Chromatography + Titration + pH indicators |
The compressive strength and hardness of diamond and various other materials, such as boron nitride, (which has the closely related zincblende structure) is attributed to the diamond cubic structure.
Similarly, truss systems that follow the diamond cubic geometry have a high capacity to withstand compression, by minimi... | 1 | Crystallography |
The elementary reaction responsible for water quantification in the Karl Fischer titration is oxidation of sulfur dioxide () with iodine:
This elementary reaction consumes exactly one molar equivalent of water vs. iodine. Iodine is added to the solution until it is present in excess, marking the end point of the titrat... | 0 | Chromatography + Titration + pH indicators |
Crystallization is largely over when reaches values close to 1, which will be at a crystallization time defined by , as then the exponential term in the above expression for will be small. Thus crystallization takes a time of order
i.e., crystallization takes a time that decreases as one over the one-quarter power ... | 1 | Crystallography |
Hydrostatic CCC or centrifugal partition chromatography (CPC) was invented in the 1980s by the Japanese company Sanki Engineering Ltd, whose president was Kanichi Nunogaki. CPC has been extensively developed in France starting from the late 1990s. In France, they initially optimized the stacked disc concept initiated b... | 0 | Chromatography + Titration + pH indicators |
Reversed phase HPLC (RP-HPLC) is the most widespread mode of chromatography. It has a non-polar stationary phase and an aqueous, moderately polar mobile phase. In the reversed phase methods, the substances are retained in the system the more hydrophobic they are. For the retention of organic materials, the stationary p... | 0 | Chromatography + Titration + pH indicators |
The basic principle of displacement chromatography is: there are only a finite number of binding sites for solutes on the matrix (the stationary phase), and if a site is occupied by one molecule, it is unavailable to others. As in any chromatography, equilibrium is established between molecules of a given kind bound to... | 0 | Chromatography + Titration + pH indicators |
In analytical chemistry, argentometry is a type of titration involving the silver(I) ion. Typically, it is used to determine the amount of chloride present in a sample. The sample solution is titrated against a solution of silver nitrate of known concentration. Chloride ions react with silver(I) ions to give the insolu... | 0 | Chromatography + Titration + pH indicators |
An eluotropic series, which orders solvents by how much they move compounds, can help in selecting a mobile phase. Solvents are also divided into solvent selectivity groups. Using solvents with different elution strengths or different selectivity groups can often give very different results. While single-solvent mobile... | 0 | Chromatography + Titration + pH indicators |
*Winkler test for dissolved oxygen: Used to determine oxygen concentration in water. Oxygen in water samples is reduced using manganese(II) sulfate, which reacts with potassium iodide to produce iodine. The iodine is released in proportion to the oxygen in the sample, thus the oxygen concentration is determined with a ... | 0 | Chromatography + Titration + pH indicators |
If we attempt to build a densely packed collection of spheres, we will be tempted to always place the next sphere in a hollow between three packed spheres. If five spheres are assembled in this way, they will be consistent with one of the regularly packed arrangements described above. However, the sixth sphere placed i... | 1 | Crystallography |
Displacement chromatography is a chromatography technique in which a sample is placed onto the head of the column and is then displaced by a solute that is more strongly sorbed than the components of the original mixture. The result is that the components are resolved into consecutive "rectangular" zones of highly conc... | 0 | Chromatography + Titration + pH indicators |
A key choice that must be made is how many atoms to explicitly include in ones calculation. In Big-O notation, calculations general scale as O(N3) where N is the number of combined ions and valence electrons. For structure calculations, it is generally desirable to choose the smallest number of ions that can represe... | 1 | Crystallography |
Cresol red can also be used as an electrophoretic color marker to monitor the process of agarose gel electrophoresis and polyacrylamide gel electrophoresis. In a 1% agarose gel, it runs approximately at the size of a 125 base pair (bp) DNA molecule (it depends on the concentration of buffer and other component). Bromop... | 0 | Chromatography + Titration + pH indicators |
A symmetry of a Euclidean graph is an isometry of the underlying Euclidean space whose restriction to the graph is an automorphism; the symmetry group of the Euclidean graph is the group of its symmetries. A Euclidean graph in three-dimensional Euclidean space is periodic if there exist three linearly independent trans... | 1 | Crystallography |
An isometry of the Euclidean plane is a distance-preserving transformation of the plane. That is, it is a map
such that for any points p and q in the plane,
where d(p, q) is the usual Euclidean distance between p and q. | 1 | Crystallography |
Comprehensive two-dimensional gas chromatography is an analytical technique that separates and analyzes complex mixtures. It has been utilized in fields such as: flavor, fragrance, environmental studies, pharmaceuticals, petroleum products and forensic science. GCxGC provides a high range of sensitivity and produces a ... | 0 | Chromatography + Titration + pH indicators |
The Freundlich adsorption isotherm is mathematically expressed as
In Freundlichs notation (used for his experiments dealing with the adsorption of organic acids on coal in aqueous solutions), signifies the ratio between the adsorbed mass or adsorbate and the mass of the adsorbent , which in Freundlichs studies was co... | 0 | Chromatography + Titration + pH indicators |
Le Bail analysis is commonly a part of Rietveld analysis software, such as GSAS/EXPGUI. It is also used in ARITVE, BGMN, EXPO, EXTRACT, FullProf, GENEFP, Jana2006, Overlap, Powder Cell, Rietan, TOPAS and Highscore. | 1 | Crystallography |
The trihexagonal tiling exists in a sequence of symmetries of quasiregular tilings with vertex configurations (3.n), progressing from tilings of the sphere to the Euclidean plane and into the hyperbolic plane. With orbifold notation symmetry of *n32 all of these tilings are wythoff construction within a fundamental dom... | 1 | Crystallography |
The first reaction of iodine with SO and water is as follows:
SO+I+2HO→HSO+2HI
As the reaction proceeds, all available SO will be consumed and the starch indicator added to the solution will bind with the unconsumed iodine, turning the solution black.
The second step of the reaction requires pretreating with solution ... | 0 | Chromatography + Titration + pH indicators |
Gas chromatography–mass spectrometry (GC–MS) is an analytical method that combines the features of gas-chromatography and mass spectrometry to identify different substances within a test sample. Applications of GC–MS include drug detection, fire investigation, environmental analysis, explosives investigation, food and ... | 0 | Chromatography + Titration + pH indicators |
The equivalence point, or stoichiometric point, of a chemical reaction is the point at which chemically equivalent quantities of reactants have been mixed. For an acid-base reaction the equivalence point is where the moles of acid and the moles of base would neutralize each other according to the chemical reaction. Th... | 0 | Chromatography + Titration + pH indicators |
Typical titrations require titrant and analyte to be in a liquid (solution) form. Though solids are usually dissolved into an aqueous solution, other solvents such as glacial acetic acid or ethanol are used for special purposes (as in petrochemistry, which specializes in petroleum.) Concentrated analytes are often di... | 0 | Chromatography + Titration + pH indicators |
In two-dimensional space there are 5 Bravais lattices, grouped into four lattice systems, shown in the table below. Below each diagram is the Pearson symbol for that Bravais lattice.
Note: In the unit cell diagrams in the following table the lattice points are depicted using black circles and the unit cells are depicte... | 1 | Crystallography |
* Orbifold signature:
* Coxeter notation (rhombic): [∞,2,∞]
* Coxeter notation (square): [(4,4,2)]
* Lattice: rhombic
* Point group: D
* The group cmm has reflections in two perpendicular directions, and a rotation of order two (180°) whose centre is not on a reflection axis. It also has two rotations whos... | 1 | Crystallography |
Scandium has the smallest atomic and ionic (3+) radii (1.62 and 0.885 Å, respectively) among the rare-earth elements. It forms several icosahedron-based borides which are not found for other rare-earth elements; however, most of them are ternary Sc-B-C compounds. There are many boron-rich phases in the boron-rich corne... | 1 | Crystallography |
In the Euclidean plane, reflections and glide reflections are the only two kinds of indirect (orientation-reversing) isometries.
For example, there is an isometry consisting of the reflection on the x-axis, followed by translation of one unit parallel to it. In coordinates, it takes
This isometry maps the x-axis to its... | 1 | Crystallography |
* Nano- and bio-organic materials: production, synthesis, structure and properties, diagnostic methods using X-ray and synchrotron radiation, electrons, neutrons and atomic force microscopy
* Fundamental aspects of the formation of crystalline materials and nanosystems, their real structure and properties
* Creation an... | 1 | Crystallography |
Methyl violet is a family of organic compounds that are mainly used as dyes. Depending on the number of attached methyl groups, the color of the dye can be altered. Its main use is as a purple dye for textiles and to give deep violet colors in paint and ink. It is also used as a hydration indicator for silica gel. Meth... | 0 | Chromatography + Titration + pH indicators |
Consider a line of atoms A-O-B, separated by distance a. Rotate the entire row by θ = +2π/n and θ = −2π/n, with point O kept fixed. After the rotation by +2π/n, A is moved to the lattice point C and after the rotation by -2π/n, B is moved to the lattice point D. Due to the assumed periodicity of the lattice, the two la... | 1 | Crystallography |
An antiphase domain (APD) is a type of planar crystallographic defect in which the atoms within a region of a crystal are configured in the opposite order to those in the perfect lattice system. Throughout the entire APD, atoms sit on the sites typically occupied by atoms of a different species. For example, in an orde... | 1 | Crystallography |
Anthocyanins are found in the cell vacuole, mostly in flowers and fruits, but also in leaves, stems, and roots. In these parts, they are found predominantly in outer cell layers such as the epidermis and peripheral mesophyll cells.
Most frequently occurring in nature are the glycosides of cyanidin, delphinidin, malvidi... | 0 | Chromatography + Titration + pH indicators |
In 1833, Adam August Krantz (who studied pharmacy and later "Geognosie" at the Bergakademie Freiberg) founded the Krantz company in Bonn. Four years later, Krantz moved to Berlin and sold minerals, fossils, rocks and basically acquired a monopoly in the production of crystal models made of pear wood or walnut. Ever sin... | 1 | Crystallography |
Closely related is mmCIF, macromolecular CIF, which is intended as an successor to the Protein Data Bank (PDB) format. It is now the default format used by the Protein Data Bank.
Also closely related is Crystallographic Information Framework, a broader system of exchange protocols based on data dictionaries and relatio... | 1 | Crystallography |
4-Nitrophenol irritates the eyes, skin, and respiratory tract. It may also cause inflammation of those parts. It has a delayed interaction with blood and forms methaemoglobin which is responsible for methemoglobinemia, potentially causing cyanosis, confusion, and unconsciousness. When ingested, it causes abdominal pain... | 0 | Chromatography + Titration + pH indicators |
Though many people conceptualize images and diffraction patterns separately, they contain principally the same information. In the simplest approximation, the two are simply Fourier transforms of one another. Thus, the effects of beam precession on diffraction patterns also have significant effects on the corresponding... | 1 | Crystallography |
The concept of Voronoi decomposition was investigated by Peter Gustav Lejeune Dirichlet, leading to the name Dirichlet domain. Further contributions were made from Evgraf Fedorov, (Fedorov parallelohedron), Georgy Voronoy (Voronoi polyhedron), and Paul Niggli (Wirkungsbereich).
The application to condensed matter physi... | 1 | Crystallography |
*A web application for determining molecular geometry indices on the basis of 3D structural files can be found [http://kchn.pg.gda.pl/geom/ here]. | 1 | Crystallography |
The Lely method, also known as the Lely process or Lely technique, is a crystal growth technology used for producing silicon carbide crystals for the semiconductor industry. The patent for this method was filed in the Netherlands in 1954 and in the United States in 1955 by Jan Anthony Lely of Philips Electronics. The p... | 1 | Crystallography |
There are 2 regular complex apeirogons, sharing the vertices of the trihexagonal tiling. Regular complex apeirogons have vertices and edges, where edges can contain 2 or more vertices. Regular apeirogons p{q}r are constrained by: 1/p + 2/q + 1/r = 1. Edges have p vertices arranged like a regular polygon, and vertex fig... | 1 | Crystallography |
The main compartment of the titration cell contains the anode solution plus the analyte. The anode solution consists of an alcohol (ROH), a base (B), sulfur dioxide () and KI. Typical alcohols that may be used include ethanol, diethylene glycol monoethyl ether, or methanol, sometimes referred to as Karl Fischer grade. ... | 0 | Chromatography + Titration + pH indicators |
LC–MS is widely used in the field of bioanalysis and is specially involved in pharmacokinetic studies of pharmaceuticals. Pharmacokinetic studies are needed to determine how quickly a drug will be cleared from the body organs and the hepatic blood flow. MS analyzers are useful in these studies because of their shorter ... | 0 | Chromatography + Titration + pH indicators |
High through-put methods exist to help streamline the large number of experiments required to explore the various conditions that are necessary for successful crystal growth. There are numerous commercial kits available for order which apply preassembled ingredients in systems guaranteed to produce successful crystalli... | 1 | Crystallography |
Methyl red displays pH dependent photochromism, with protonation causing it to adopt a hydrazone/quinone structure.
Methyl Red has a special use in histopathology for showing acidic nature of tissue and presence of organisms with acidic natured cell walls.
Methyl Red is detectably fluorescent in 1:1 water:methanol (pH ... | 0 | Chromatography + Titration + pH indicators |
Physical properties of interest to materials science among perovskites include superconductivity, magnetoresistance, ionic conductivity, and a multitude of dielectric properties, which are of great importance in microelectronics and telecommunication. They are also some interests for scintillator as they have large lig... | 1 | Crystallography |
Bromothymol blue may be used for observing photosynthetic activities, or as a respiratory indicator (turns yellow as CO is added). A common demonstration of BTB's pH indicator properties involves exhaling through a tube into a neutral solution of BTB. As CO is absorbed from the breath into the solution, forming carbon... | 0 | Chromatography + Titration + pH indicators |
Swansea University has had a long established history of development and innovation in mass spectrometry and chromatography. | 0 | Chromatography + Titration + pH indicators |
Real-life crime scene investigators and forensic scientists warn that popular television shows do not give a realistic picture of the work, often wildly distorting its nature, and exaggerating the ease, speed, effectiveness, drama, glamour, influence and comfort level of their jobs—which they describe as far more munda... | 0 | Chromatography + Titration + pH indicators |
* Paper form: It is a strip of coloured paper which changes colour to red if the solution is acidic and to blue, if the solution is basic. The strip can be placed directly onto a surface of a wet substance or a few drops of the solution can be dropped onto the universal indicator using dropping equipment. If the test s... | 0 | Chromatography + Titration + pH indicators |
In geometry, a sphere packing is an arrangement of non-overlapping spheres within a containing space. The spheres considered are usually all of identical size, and the space is usually three-dimensional Euclidean space. However, sphere packing problems can be generalised to consider unequal spheres, spaces of other dim... | 1 | Crystallography |
The surface advances by the lateral motion of steps which are one interplanar spacing in height (or some integral multiple thereof). An element of surface undergoes no change and does not advance normal to itself except during the passage of a step, and then it advances by the step height. It is useful to consider the ... | 1 | Crystallography |
The Kovats index applies to organic compounds. The method interpolates peaks between bracketing n-alkanes. The Kovats index of n-alkanes is 100 times their carbon number, e.g. the Kovats index of n-butane is 400. The Kovats index is dimensionless, unlike retention time or retention volume. For isothermal gas chromatogr... | 0 | Chromatography + Titration + pH indicators |
Okano’s group expanded on their success by using different modifiers to enhance hydrophobicity through the attachment of butyl methacrylate (BMA), a hydrophobic comonomer. For simplification the resultant polymer has been labeled as IBc (isopropylacrylamide butyl methacrylate copolymer). The polymers were synthesized u... | 0 | Chromatography + Titration + pH indicators |
The columns used in FPLC are large [mm id] tubes that contain small [µ] particles or gel beads that are known as stationary phase. The chromatographic bed is composed by the gel beads inside the column and the sample is introduced into the injector and carried into the column by the flowing solvent. As a result of dif... | 0 | Chromatography + Titration + pH indicators |
Fischer and Jandera studied the effect of changing the concentration of methanol on CMC values for three commonly used surfactants. Two cationic, hexadecyltrimethylammonium bromide (CTAB), and N-(a-carbethoxypentadecyl) trimethylammonium bromide (Septonex), and one anionic surfactant, sodium dodecyl sulphate (SDS) we... | 0 | Chromatography + Titration + pH indicators |
The Tensorial Anisotropy Index A extends the Zener ratio for fully anisotropic materials and overcomes the limitation of the AU that is designed for materials exhibiting internal symmetries of elastic crystals, which is not always observed in multi-component composites. It takes into consideration all the 21 coefficie... | 1 | Crystallography |
Methyl yellow, or C.I. 11020, is an organic compound with the formula CHNCHN(CH). It is an azo dye derived from dimethylaniline. It is a yellow solid. According to X-ray crystallography, the CN core of the molecule is planar.
It is used as a dye for plastics and may be used as a pH indicator. In aqueous solution at ... | 0 | Chromatography + Titration + pH indicators |
Silver ions form alkene complexes. The binding is reversible, but sufficient to impede the elution of the alkene-containing analytes. | 0 | Chromatography + Titration + pH indicators |
Difference density maps are usually calculated using Fourier coefficients which are the differences between the observed structure factor amplitudes from the X-ray diffraction experiment and the calculated structure factor amplitudes from the current model, using the phase from the model for both terms (since no phases... | 1 | Crystallography |
Symmetries in nature lead directly to conservation laws, something which is precisely formulated by Noether's theorem.
The basic idea of time-translation symmetry is that a translation in time has no effect on physical laws, i.e. that the laws of nature that apply today were the same in the past and will be the same in... | 1 | Crystallography |
In solid state physics, a superstructure is some additional structure that is superimposed on a higher symmetry crystalline structure. A typical and important example is ferromagnetic ordering.
In a wider sense, the term "superstructure" is applied to polymers and proteins to describe ordering on a length scale larger ... | 1 | Crystallography |
Confusion between inversion domains and antiphase domains is common, even in the published literature, and particularly in the case of GaAs grown on silicon. (Similar defects form in GaN on silicon, where they are correctly identified as inversion domains). An example is illustrated in the diagram below.
Figure 4. Hi... | 1 | Crystallography |
Booth designed an electromechanical computer, the ARC (Automatic Relay Computer), in the late 1940s (1947-1948). Later on, they built an experimental electronic computer named SEC (Simple Electronic Computer, designed around 1948-1949) - and finally, the APE(X)C (All-Purpose Electronic Computer) series.
The computers ... | 1 | Crystallography |
Ion chromatography (or ion-exchange chromatography) is a form of chromatography that separates ions and ionizable polar molecules based on their affinity to the ion exchanger. It works on almost any kind of charged molecule—including small inorganic anions, large proteins, small nucleotides, and amino acids. However, i... | 0 | Chromatography + Titration + pH indicators |
In liquid crystals, homeotropic alignment is one of the ways of alignment of liquid crystalline molecules. Homeotropic alignment is the state in which a rod-like liquid crystalline molecule aligns perpendicularly to the substrate. In the polydomain state, the parts also are called homeotropic domains. In contrast, the ... | 1 | Crystallography |
The number of theoretical plates, or separation efficiency, in capillary electrophoresis is given by:
where is the number of theoretical plates, is the apparent mobility in the separation medium and is the diffusion coefficient of the analyte. According to this equation, the efficiency of separation is only limited... | 0 | Chromatography + Titration + pH indicators |
Consider the scattering of a beam of wavelength by an assembly of particles or atoms stationary at positions . Assume that the scattering is weak, so that the amplitude of the incident beam is constant throughout the sample volume (Born approximation), and absorption, refraction and multiple scattering can be neglec... | 1 | Crystallography |
The Gran plot is based on the Nernst equation which can be written as
where E is a measured electrode potential, E is a standard electrode potential, s is the slope, ideally equal to RT/nF, and {H} is the activity of the hydrogen ion. The expression rearranges to
depending on whether the electrode is calibrated in mill... | 0 | Chromatography + Titration + pH indicators |
Laser spray ionization refers to one of several methods for creating ions using a laser interacting with a spray of neutral particles or ablating material to create a plume of charged particles. The ions thus formed can be separated by m/z with mass spectrometry. Laser spray is one of several ion sources that can be co... | 0 | Chromatography + Titration + pH indicators |
RHEED is an extremely popular technique for monitoring the growth of thin films. In particular, RHEED is well suited for use with molecular beam epitaxy (MBE), a process used to form high quality, ultrapure thin films under ultrahigh vacuum growth conditions. The intensities of individual spots on the RHEED pattern flu... | 1 | Crystallography |
ScBSi has a tetragonal crystal structure with space group P422 (No. 92) or P422 and lattice constants of a, b = 1.03081(2) and c = 1.42589(3) nm; it is
isotypic to the α-AlB structure type. There are 28 atomic sites in the unit cell, which are assigned to 3 scandium atoms, 24 boron atoms and one silicon atom. Atomic co... | 1 | Crystallography |
The main advantages of this technique are the high pulling rates (60 times greater than the conventional Czochralski technique) and the possibility of growing materials with very high melting points. In addition, LHPG is a crucible-free technique, which allows single crystals to be grown with high purity and low stress... | 1 | Crystallography |
A sculpture titled Bamboozle, by Jacobus Verhoeff and his son Tom Verhoeff, is in the form of a fragment of the Laves graph, with its vertices represented by multicolored interlocking acrylic triangles. It was installed in 2013 at the Eindhoven University of Technology. | 1 | Crystallography |
Water is particularly common solvent to be found in crystals because it is small and polar. But all solvents can be found in some host crystals. Water is noteworthy because it is reactive, whereas other solvents such as benzene are considered to be chemically innocuous. Occasionally more than one solvent is found in... | 1 | Crystallography |
If the illuminated area selected by the aperture covers many differently oriented crystallites, their diffraction patterns superimpose forming an image of concentric rings. The ring diffractogram is typical for polycrystalline samples, powders or nanoparticles. Diameter of each ring corresponds to interplanar distance ... | 1 | Crystallography |
In crystallography, an anti-structure is obtained from a salt structure by exchanging anion and cation positions.
For instance, calcium fluoride, CaF, crystallizes in a cubic motif called the fluorite structure. The same crystal structure is found in numerous ionic compounds with formula AB, such as ceria (CeO), zirc... | 1 | Crystallography |
In physics, the phase problem is the problem of loss of information concerning the phase that can occur when making a physical measurement. The name comes from the field of X-ray crystallography, where the phase problem has to be solved for the determination of a structure from diffraction data. The phase problem is al... | 1 | Crystallography |
Although there is a large number of simple known ABX perovskites, this number can be greatly expanded if the A and B sites are increasingly doubled / complex AA’BB’X. Ordered double perovskites are usually denoted as ABB’O where disordered are denoted as A(BB’)O. In ordered perovskites, three different types of orderin... | 1 | Crystallography |
Affinity purification of albumin and macroglobulin contamination is helpful in removing excess albumin and α-macroglobulin contamination, when performing mass spectrometry. In affinity purification of serum albumin, the stationary used for collecting or attracting serum proteins can be Cibacron Blue-Sepharose. Then the... | 0 | Chromatography + Titration + pH indicators |
* Positions of the CBED disks are the same as the positions of the Bragg peaks and are given approximately by the relation:
where is the distance between the crystallographic planes , is the Bragg angle, is an integer, and is the wavelength of the probing electrons.
* The beam convergence semi-angle - is controll... | 1 | Crystallography |
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